Boiler



Patented Feb. 26, 1929.

UNITED STATES Homan ADDAMs, or" oswneo, NEW YORK.

BOILER.

Application filed .Tuly 1, 1926. Serial No. 119,817.

rlhis invention relates in general to boilers and more particularly to boilers having two passes of iiues.

Among the objects of the present invention, it is aimed to provide a new construction of boiler in which for a given lire grate area or combustion surface, the space occupied by the fines relative to the tire box is very compact, so that a much smaller space is occupied by the boiler proper, giving a much wider range of use for this type of boiler and at the same time enhancing the enciency of the boiler from the standpoint of cost of construction and cost of upkeep for a` given work capacity.

It is further aimed to provide an improved construction for boilers in general.

These and other features, capabilities and advantages of the invention will appear from the subjoined detail description of one specific embodiment thereof illustrated in the accompanying drawings, in which Figure 1 is a plan of a boiler made according to the present invention.

Fig. 2 is a section substantially on the line 2-2 of Fig. 1.

Fig. 3 is a front elevation.

rlllhe boiler consists essentially of a front main portion A and a rear extension B, the outline of the rear extension being substantially oblong, the upper curved surface of which being merely a continuation of the upper curved surface of the front portion A, the outline of the lower end of the front portion A being substantiallyl rectangular' as shown in Fig. 3.

The boiler has an. outer shell consisting of a front plate 1 provided with an opening 2 for the fire door and provided with a chimney xtension 3 above said fire door, a second main plate, the inverted Ushaped plate 5 which is riveted to the front plate 1 at 4 and extends from the lower end of one side of the portion A and continues up and into the curved part 6 of the portion A and then continues down the 'fther side of the portion A to the bottom thereof, third main plate 7 formed in the ('utline of the curved Wall of the portion B andriveted to the upper curved part 6 of the plate 5 at 8. and a fourth plate 9 substantially plane in surface and having an upper recessed portion to receive the plate 7 and riveted to the plate 7 at 10 and to the plate 5 at 11. The plates 5 and 7 may be made of one continuous plate but are preferably made separate and attached to one another as there welded to such plate.

shown. The rear endof the `portion B is provided with. a suitable closure member 12. The inner shells or wall members of the furnace are preferably welded to the outer shell member and to one another as now to be described and constitute an important part of the present invention.

Spaced from and substantially parallel to the closure 12 there is provided a plate 13 which is welded throughout its periphery to the plate 7, and is provided with openings to receive the flue pipes 14 and 15. The plate 1, registering with the chimney portions 3, is provided with suitable openings 16 to receive the outlet ends of the upper iiue pipes 15. The flue pipes 15 are thus secured to the plate 1 and the plate 13 and supported thereby to afford access between the chamber 17 formed between the closure 12 and the plate 13. and the vchimney portion 3. The innerv wall 18 of the fire box 19 is spaced from the plate 1, the plate 9 and the plate 6 to form a water aclet for the fire box. The inner wall 18 has a front plate 2O which is welded around the opening 2 to the plate 1, and has a second plate 21, a third plate 22 and a fourth plate 23 which are welded to one f another at their adjacent edges as illustrated in Fig. 2.` The plate 21 extends from the bottom of one side of the fire box, one part thereof, being U-shaped, continuing over the front or high portion H of the fire box 19 and down to the lower end of the other side of the lire box 19, and the rear parts 24 of the plate 21 merely extending up to the plate 23 and being It will be seen that the plate 21 of the fire box 19 is recessed to receive the plate 22 to form an L-shape in side elevation. The plate 22 has a lower horizontal part 25 and continuing therefrom upwardly an upper vertical part 26. By this means the upper portion of the fire box will have a diminished front part H, the plate 22 virtually extending into the ire box 19 to close olf the upper rear part thereof. By this means it will be seenthat the lower part of the fire box 19 will be left intact in order to afford an extended [ire grate area or combustion surface and the upper portion H constricted. The vertical section 26 of the plate i 22 is provided with a plurality of openings 27 to receive the front ends of the lower flueA pipes 14. Thus itwill be seen that the Hue pipes 14 will be supported at their front ends by the plate 22 and at their rear ends by the front portions ofthe flue pipes 14 Where they receive the hot gases of combustion from the fire chamber Will havelnot lonly their inlet portions exposed to the fire chamber but also will have a substantial length of them extend-y ing into the area arbitrarily designated as 28 and over the rear portion of the fire box. The area 28 is that portion of the boiler formed by the bent plate 22.

The plate 7 is provided with an opening 29 serving as the inlet for the Water to the Water chamber W. The plate 7 is also provided Witha steam outlet 30. The plate is provided with a manhole 31 and a safety valveopening 32. The plate 9 at the lower end` thereof adjacent to the lower end of the plate 23 is provided With a blow-off or drain opening 33.

f ltv may also be desirable to supply suitable stays 35 connecting the plate 2l and the horizontal part 25 of the plate 22 with the curved part 6 of the plate 5. Suitable stays 3G may also be provided to connect the sides of the plate 5 and the plate 7 with one another properly to brace the same. Furthermore, in some cases it may also be desirable to provide stays 37 connecting the vertical part of the plate 217With the plate 9, as indicated in Fig. 1.

v:tn the operation of this boiler, the gases of combustion will pass through the sheet 22 into the'fiue pipes 14 and out through the rear ends thereof into the chamber 17 and from there through the shield 13 into the flue pipes 15 `and out through the front end of the flue pipes l5 in to the chimney ineinber 3.

From the foregoing it will be seen that the section of the plate 22 will be heated by the fire grate to heat the area 28 of the chamber W, and also directly Vheat, the plate 21 to heat the y*arca 34 of the chamber W, above the plate 21, and at the same time supply the hotgases forthe lflue pipes 14:, the construction of the tire box serving` to secure intimate intermingling of the gases from the tire with the oxygen of the air, thus attaining more perfect combustion andincreasiug their temperature prior to their passage through the flue pipes, lll, and thus securing more effective transfer of heat from the gases to the water surrounding the iue pipes and the iirc box.

fly means of the foregoing, it will also be seen that by forn'iing the area 28 and thus extending the front ends of the flue pipes 14 substantial distance intothe fire box 1S, for a given lire grate area and the consequentl flue pipe area, withja two-pass boiler the length of the boiler is materially decreased. In other words, with a two-pass boiler having flue pipes la going one way and iiue pipes 15V" directing the hot gases in the ,opposite direc tion, in order to obtain the same I'lue pipe heating surface, the boiler Would have to bc considerably longer, at least one-half of the length of the part 25 of the section 22. In

otheravordsf merely a one-pass boiler' were used, merely having the flue pipes 111 extendinginfone direction in order to obtain the same heating surface of Hue pipe, Without the area 28, the boiler would have to be longer by a distance equal about to the length of the area 28or=the part 25 of the plate 22. ln vienT of the fact, however, that the areas 28 and 34 are disposed directly above and substantially in I intimate contact with the lire box, experience has taught that for a given eiiiciency the flue pipes can be diminished still furtheras compared to a boiler in which the front ends of the flue pipes do not extendy into thclire box.

1t has also been found that byformingthe constricted portion-H, thereby increasing the temperature of the gases fed up into such constricted area resulting in an increased rate of heat transfer through the Walls of the flue pipes as compared to a similar boiler Without such eonstricted chamber, a substantially vless surface of flue pipe is required to vobtain a given heating result.

lt is furthermore to be `noted from the construction above described that by Welding the `joints of the inner Wall 'a decidedlycheaper construction can be p'roducedivithout impairing the. efleiency or longevity of the boiler.

From the foregoing it Will also be seen that, since the water enters into the portion B to the right of the tire boX, the coolest area Will be that indicated generally by the reference character' 38, and the hot-testheating area, the area designated 28, due toits proximity to the .tire boX and also to its contact with the hottest portion of iue pipes, to Wit the entering portions of the flue pipes 14,1that the second hottest area willv be thevarea 34: directly above the constricted chamber portion H of the lire boXand that the third hottest portion of the chamber W, or the second coolest portion of the chamber W will be the area designated generally by the reference character 39. By these successive areas of varyingtempcrature graduating one into the other in order, a free circulation of the Water Ais effected, to Wit from the coolest area 3S to the hottest area 2S and then upward to the next succeeding area 84- less hot than the arca28, and then laterally rcarvf'ard to the next arca 39 less hot than the arca and thenback to the coolest area 38.

It is of course. obvious that certain changes and modiiications may be made to the details of construction without departing from the general spirit of the invention as set forth in the appended claims.

claim t,

l. Ina steam boiler, the combination with a firebox rectangular in horizontal cross scc* tion and having an upper eonstricted eXtension at its front end,`of{ a fire door formed in the front end of said iir'ebox, a housing, a shield mounted in said housing and spaced a short distance from the rear end of said housllO ing to form a return chamber for the flue gases between said rearend and said shield and water reservoir to the front thereof, the lower portion of the housing extending trein the rear tace of the constricted extension of said ii'rebox and across and beyond the rear end of the irebox, the upper' portion of the housing' extending across the top ot the constrieted extension of the lirebox, a lower group oi'l flue pipes extending` through. the lower portion or said housing from the rear face of said veonstrieted extension to said shield to form communication between the tirebox and the return chamber, a second group of tlue pines extending' through the upper portion of said housing' from the shield to the front end oi said housing, and a chimney member in communication with the 'lront end of said upper [group or flue pipes.

2. ln a steam boiler, the combination with a firebox rectangular' in horizontal cross seetion and haring an upper eonstrieted extension at its front end, of a lire door formed in the liront end of said lirebox, a housing', a shield mounted in said housing' and spaced a short distance from the rear end of said housing to form a return chamber for the flue gases between said rear end and said shield and a water reservoir tothe front thereof, the lower portion of the housing` extending,` from the rear tace of the constrieted extension of said irebox and across and beyond the roar end of the lirebox, the upper portion of the housing extending across the top of the constricted extension of the lirebox, a lower group of lue pipes extending' through the lower portion oit' said housing;` from the rear face of said constrieted extension to said shield to form communication between the Firebox and the return chamber, a second group of flue pipes extending' througl'i the upper portion oit said housing from the shield to the iront end of said housing, a water inlet in the bottom ol said housing to the rear oi said lirebox, and a steam outlet in the top of said housing to the rear ot said lirebox.

3. ln a. steam boiler, the combination with a housing; comprising` a main outer shell portion havingl a downward extension rectangular in horizontal cross section and a rear tubular outer shell'extension riveted to the rear upper end olf said main outer shell portion. of an inner shell in said main outer shell portion having' a eonstricted portion at its upper end to 'torni a. lire-box havini@r an upper constricte'd extension at its` 'front end and forming' with the main outer shell portion a water jacket along the sides oli' the lower portion of said lire-box, a shield mounted in said housing and spaced a short distance from the rear end of said tubular extension to form a return chamber for the flue gases between said rear end and said shield and to form a water reservoir to the front of said shield, a lower group of Hue pipes extending through the lower portion of said housing from the rear tace of saideonstricted extension to said shield to forni communication between the tire-box and the return chamber, a. second group ot flue pipes extending through the upper portion of said housing from the shield to the front end `ot' said main outer shell, and a chimney member in comn'iunieation with the front end of said upper group of flue pipes.

4. In a steam boiler, the combination with an outer shell having' a curved rearward portion, a main inverted U-shaped plate, a plane front plate and a plane intermediate recessed plate, the plane front plate being' riveted to the front edge of the inverted U-shaped plate, the upper curved part `of the inverted U- shaped plate being riveted to the upper curved part of the rearward portion and the recessed plate being riveted both to theinverted U-shaped plate and to the rearward portion to connect the two and form an outer shellhaving a front downward extension reeyt-angular in horizontal cross sect-ion; a door for the rear end of the rearward portion; a shield spaced. from the doorv and welded to the rearward portion to form a` return chamber; an inner wall forming a ,tirebox and al water jacket for the irebox with the downward extension of the outer shell, the inner *wall having an inverted U-shaped plate reeessed at its rear upper end to simulate an L- shape, a front plate welded to the front edge of the inverted U-shaped plate of the inner wall also having a rear plate welded to the rear edges of the inverted U-shaped plate, and also having a bent plate welded to the edges of the recessed portion of its inverted U- shaped plate; a fire door formed in the front plates or' the outershell and inner wall; a group of flue pipes extending from thesbent plate of the inner wall to the shield to aflord communication between the lire box and the ret-urn chamber; and a second group of flue pipes extending from the shield to the front plate of the outer shell and affording communication between the return chamberl and the atmosphere, the curved rearward portion and main inverted U-shaped plate forming a steam chamber above, and the full length of, the second group of flue pipes.

5. In a steam boiler, the coinbiluition with a water reservoir having` aI steam chamber aboveand the lull length thereof, a lower group oi" flue pipes passing therethrough to coni/'env the iiue gases therethrough in one direction, an upper `group of iiue pipes extending through said water reservoir to conduct 'the flue gases through said reservoir in the opposite direction to the direction of the flue gases in the lower group, there being a Communication between said lower lgroup of flue pipes and said upper group of flue pipes 'to permit the flue gases from the lower group to pass into the upper group, a water inlet llO at the bottomof the rear yportion ofthe reser- Voir, .a fire .boxwreetangularin horizontal crossiseetion underthe lower part of the front portion .of vthe reservoir, a ire door in the front end of .the iirebox, the portion of the reservoiry containing the .front ends of the lowergroup of flue pipes extending into, and above the rear end 4of the ire box to form an intensive heating area, and. the portion of the reservoir Containing the outlet ends of the upper groupof flue pipes disposed above the upper end of the re box to form a less intensive heating area, wherebyv the "cool water from the water inlet will be caused to pass to the intensive heating area. of the reservoir, then to the less intensive heating area of the reservoir and then rearward through the up'- per portion of the reservoir back to the lower portion of vthe reservoir to efect'a free eireulation of the water.

HOMER ADDAMS. 

